> On 1 Nov 2019, at 22:10, Alan Grayson <agrayson2...@gmail.com> wrote: > > > > On Friday, November 1, 2019 at 3:57:39 AM UTC-6, Bruno Marchal wrote: > >> On 31 Oct 2019, at 23:49, Alan Grayson <agrays...@gmail.com <javascript:>> >> wrote: >> >> >> >> On Thursday, October 31, 2019 at 6:04:58 AM UTC-6, Bruno Marchal wrote: >> >>> On 30 Oct 2019, at 21:50, Alan Grayson <agrays...@gmail.com <>> wrote: >>> >>> >>> >>> On Tuesday, October 29, 2019 at 5:53:10 PM UTC-6, Alan Grayson wrote: >>> >>> On Tuesday, October 29, 2019 at 5:18:45 PM UTC-6, Brent wrote: >>> >>> On 10/29/2019 3:48 PM, Alan Grayson wrote: >>>> >>>> On Tuesday, October 29, 2019 at 1:55:17 PM UTC-6, Brent wrote: >>>> >>>> >>>> On 10/29/2019 12:46 PM, Alan Grayson wrote: >>>>> >>>>> >>>>> On Tuesday, October 29, 2019 at 1:25:43 PM UTC-6, Brent wrote: >>>>> >>>>> >>>>> On 10/29/2019 11:43 AM, Alan Grayson wrote: >>>>>> What does that mean? No one even detects them. They need not even be >>>>>> absorbed, but could simply fly off to infinity. >>>>>> >>>>>> Brent >>>>>> >>>>>> What exactly is the situation? Interference is destroyed, more and more, >>>>>> as they get hotter, but without any observations? AG >>>>> >>>>> Right. >>>>> >>>>> Brent >>>>> >>>>> It sounds like some sort of hidden variable (don't take this too >>>>> literally), where the particles send out information of whether >>>>> interference will occur or not, and it doesn't matter if it's observed. >>>>> This could fit into my model of superposition with some modification; >>>>> namely, it you do a which-way experiment, OR if information about >>>>> which-way is available, interference is destroyed. And what goes through >>>>> the slits in the absence of these conditions is a wave going through both >>>>> slits. AG >>>> >>>> OK. Except "send out" doesn't make sense. It implies signaling, which >>>> would be at less than light speed (c.f. delay choice quantum eraser >>>> experiment). >>>> >>>> Brent >>>> >>>> What descriptive term do you prefer? Those IR photons travel at the SoL. >>>> The point is that if there's information available for which-way, even if >>>> not observed, the interference is destroyed. AG >>> >>> What does "available" mean? The information that left at the speed of >>> light is not "available" in any conventional sense at the screen or >>> detector in the experiment. >>> >>> Brent >>> >>> That's the mystery we have to figure out. What we know, is that the >>> particles release IR photons which could be observed, and when that >>> emission occurs, interference disappears. It doesn't even depend on any >>> observations being made. AG >>> >>> I would revise my interpretation this way; the electron, or whatever, >>> behaves as a wave when no information exists to distinguish which-way, and >>> that wave goes through both slits producing interference. When such >>> information exists, even if it isn't used or measured, the interference >>> ceases to exist. Obviously, there's a huge mystery how the existence of >>> such information is sufficient to destroy interference, but that's what the >>> experimental results demonstrate. AG >> >> That huge mystery disappears when you apply QM to the particles *and* to the >> observers and all things they interact with. The interferences are never >> destroyed, >> >> >> I don't see how this simplifies anything. Sometimes the local observer sees >> interference; sometimes not depending on whether which-way information >> exists. How does your model explain this? AG > > Take the cat C, assuming it well isolated in its box. The cat is in the state > 1/sqrt(2) (a + d). Now imagine that the box was not so well isolated, and > some particle P interact with it. Let us describe the state of the particle, > in case the cat would ba alive by P_a, and P_d if the cat was dead. As the > cat is in the state a + d, the new state is: > 1/sqrt(2) (P_a a + P_d d). OK? > > If I was ware of that particles, I could in principle obtain interference > pattern from that (pure) superposition. In particular, I could erase the > “memory” of the interaction of the particle, so that I can factor again P > from the state above, and get back the interference available from a + d. > > But if I cannot track that particle, I am unable to do that, and the > interaction with the particle has destroyed my mean to get back to the a + d > state, and I am confronted with what I will take as a mixed state. It looks > like a collapse, but it is only because the superposition of the cat has > leaked to the environment in a way making impossible for me to get back to > the a + d state. > > So, there is no collapse, but the fact that the superposition has leaked in > the environment, without me knowing any details on this, makes the state of > the cat equivalent to a mixture of a and d state. FAPP, the cat is either > dead or alive after that unknown and untrackable information. > > We see that a measurement is only an entanglement, and we don’t need a > collapse postulate to explain why even an “unknown measurement made by some > cosmic particle” prevents me to keep the superposition of the cat available > to me. > > Bruno > > Forget about collapse or no collapse; forget about cats.
I cannot really do this when confronted with a superposition. To get the observed mixed state from the SWE only, I need to consider the superposition of myself, even if I observe only an electron. > The fact is that with electrons or whatever, sometimes we see interference > patterns, and sometime not. In the latter case it occurs when which-way > information exists, and it doesn't matter if we use or observe that data by > instruments or by human observers. Exactly, that is the main reason to choose “MW” instead of a collapse. > I don't see how your previous message remotely offers an explanation. AG Well, in once case we can factor me on the a + d, or up + down state, but once a particle that I am unaware of has interact with the object (micro or macro) described by a + d, or up + down, I can no more factorise the wave, and I can see only a mixed state. Reread my last post with this in mind, it is very basic quantum mechanics (without collapse). Bruno > > > > >> >> but assuming that the observers are machines and that they obey to QM >> explains entirely why they feel like memorising that the interference have >> disappeared, and why they are locally right about this. >> >> Either the observer obeys QM, and inherits the superposition of what they >> are observing through measurement/entanglement, or QM is false for the >> observer, and we have to wait for some theory of what is an observer, >> together with some criteria for when and where we can use QM. >> >> Bruno >> >> >> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Everything List" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to everyth...@googlegroups.com <>. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/everything-list/9d13eee6-5f1c-4a0d-a51a-4a8a6474ff0e%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/everything-list/9d13eee6-5f1c-4a0d-a51a-4a8a6474ff0e%40googlegroups.com?utm_medium=email&utm_source=footer>. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Everything List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to everyth...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/everything-list/9facd6dd-7ab5-483a-84c9-83f58b9c7c92%40googlegroups.com >> >> <https://groups.google.com/d/msgid/everything-list/9facd6dd-7ab5-483a-84c9-83f58b9c7c92%40googlegroups.com?utm_medium=email&utm_source=footer>. > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com > <mailto:everything-list+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/04322a49-feef-4f0c-97ce-e5ae51c9e5ef%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/04322a49-feef-4f0c-97ce-e5ae51c9e5ef%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/A5002BEA-9726-4440-9425-43523472B098%40ulb.ac.be.
